Chapter 17

Solid, liquid, gas, and plasma.

No, they have a variety of speeds.

The change oh phase from liquid to gas that occurs at the surface of a liquid.

Evaporation is a cooling process because energy that is taken from the remaining liquid by those molecules undergoing a phase change causes the temperature of the remaining liquid to decrease.

The change of phase from solid to gaseous, bypassing the liquid phase.

Condensation is the changing of a gas to a liquid. Evaporation is the changing of a liquid to gas.

Steam contains more energy than boiling water of the same temperature.

Humid days have a lot of moisture in the air. So when its hot and humid, your sweat cannot evaporate as well as it does on hot, dry days - which makes you sweat even more.

Humidity is a measure of the amount of water vapor. Relative humidity is the ratio of the amount of water vapor currently in the air at a given temperature to the greatest amount of water vapor the air can contain at that temperature.

As the air rises, it cools and condenses to form clouds.

Altitude.

When evaporation occurs beneath the surface of a liquid, it is said to be boiling.

Increase the boiling point of water.

The higher temperature cooks food faster.

Because of the immense pressure at the bottom of the ocean is unable to turn to gas so does not actually boil. It remains in a super heated liquid state and quickly rises through the colder water until the water pressure is such that the water can expand into gas or cools to the temperature of the water around it.

Since the pressure at the bottom of a column of water is directly proportional to the depth, when water gushes out, the pressure at the bottom is reduced.

Because adding energy pulls apart the attraction among the molecules and therefore go into potential energy.

When the air pressure above is reduced?

Increased temperature means increased motion, which means more chance of molecule separation

Decreased temperature means decreased motion, which means less chance of molecule separation and more chance of sticking together.

Foreign ions decrease the number of water molecules at the interface between ice and water where freezing occurs.

Because H2O molecules form open structures in solid phase, the application of pressure lowers the melting point of ice. The crystals are crushed to the liquid phase.

The block doesn't separate into two pieces because the water above the tire refreezes when pressure on it is reduced.

A liquid absorbs energy when it changes into a gas.

A liquid releases energy when it changes into a solid.

Heat is discharged by condensation.

One calorie; 80 calories; 540 calories.

Hot coals have a low conductivity, and water on wet feet absorbs a lot of energy as it vaporizes. Energy that would normally go into burning skin instead does into changing the phase of water on the skin. The energy converts the water into vapor, an insulating layer between the feet and coals.

Wet. The energy that vaporizes water is energy that doesn't burn your feet.

Condensation.

Cools the water being boiled and depends on atmospheric pressure. Boiling is also a change of phase below the water surface.

warmed. The change of phase is from gas to solid, which releases energy.

Condensing 1 gram of 100ºC steam to 100º water

Melts. For each gram of ice that melts, 540 calories is taken from the beverage.